Like all Pattern Scout patterns, the Byrdie Button-up pattern comes in US sizes 0-28 with B, C, and D cup sizing options. Since this pattern is designed to have a good amount of ease through the bodice with a closer fit in the shoulders, it is very important to select your size based on the upper bust measurements in the Size Chart. A Finished Garment Measurements chart is also provided for fit reference, but sizing should START at the Size Chart.

The Size Chart includes a “high bust” and a “bust” (aka, full bust) measurement that correspond to the B cup size. If your high bust (measured around the bodice above the bust and right under your armpits) is 36 inches, for example, and your full bust (measured around the bodice at the fullest part of your bust) is 38 inches—a difference of 2”—you will select size 12, B cup and print the corresponding file. If your high bust is 36 inches and full bust is 39 inches, you will select size 12 C cup since there is a difference of 3”. And for a difference of 4” between the high bust and full bust, select the D cup for your size.

Now, you may be able to get away without sizing up to a larger cup size if you are right on the edge of a size. This is when you will refer to the Finished Garment Measurements to ensure that the size you are considering has approximately 4 to 6 inches of ease in the bust (this may sound like a lot, but this ease works well with the intended fit and style of the finished garment). The finished garment measurements are also provided to give you an idea of the overall length of the finished garment bodice and sleeves, as well as the bicep and hem circumferences. These measurements are most handy for deciding if you’ll need to make any adjustments to widths and circumferences of the pattern pieces (such as shortening/lengthening the pattern pieces or doing a full bicep adjustment).


The fit is designed to be loose below the bust, so if you want a closer fit, it is recommended to grade from your suggested size in the shoulders and bust to the smaller size below the bust. This will ensure that the blouse fits properly in the shoulders and underarms. If you size down the entire garment, it will likely be too tight in the shoulders and across the high bust (this was verified during testing).

If your hip measurement falls under a larger size than your bust measurements, you probably don’t need to grade between sizes if it is only a 1 to 2 size difference. The waist and hips have generous ease, so refer to the Finished Garment Measurements to verify the ease in the hips before deciding to grade between sizes.

And, not that I want you to NOT buy and sew the Byrdie ;)…but if you are looking for a more fitted blouse, you may want to search for a more fitted pattern elsewhere. Altering the the ease too much may result in a fit that you are unhappy with overall.


When I designed this pattern, I pictured it in light to medium weight, woven fabrics, such as cotton shirting or rayon. But it can also be sewn up in more crisp cottons and linens for a more structured and preppy fit.

If sewing the Version A Blouse, I recommend both fluid AND crisp fabrics, as the classic details will work really well with both structured and lighter weight fabrics. Cotton, linen, flannel, rayon challis, tencel, lyocell, and silk noil are all suitable fabrics (and I’m sure I left out a few…basically any light to medium weight woven fabric that you’d like a shirt made out of!).

Crisp medium weight quilting weight cotton

Lightweight cotton flannel with contrast quilting cotton plackets, collar, and pockets


Lightweight white tissue linen (this has become my favorite shirt to wear!)


For Version B Blouse and the Dress option of both Versions, I recommend something with a lighter weight, such as rayon, cotton lawn, silk, crepe, chiffon, tencel, or lyocell. These fabrics will hang in a really nice silhouette and will not add too much bulk in the skirt or for the tucks across the bust of Version B.

Lightweight lyocell denim (and I added pockets to this one)

Cotton lawn worked very well for the Version B blouse tucks!


I also used tencel twill for this version which turned out beautiful! But it *was* slightly a pain and quite shifty when pressing all hose tucks.


And you can always experiment with fabrics—these are only suggestions and I encourage playing with the silhouettes to get a finished result you love (one of the testers even made a beautiful dress in corduroy!).

You can see more examples of Byrdie inspiration on Part 1 of the sewalong and over on the Byrdie Tester Roundup.

September 22, 2020 — Casey Sibley